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排序方式: 共有206条查询结果,搜索用时 15 毫秒
61.
62.
S Mui M Briggs H Chung RB Wallace T Gomez-Isla GW Rebeck BT Hyman 《Canadian Metallurgical Quarterly》1996,47(1):196-201
Apolipoprotein E allele 4 (apoE epsilon 4) is a major risk factor for late-onset AD. Inheritance of this allele is associated with an earlier age of onset of dementia in individuals with AD. It is unknown whether other polymorphisms in the apoE gene may influence the effect of apoE epsilon 4 on AD. We screened portions of the promoter enhancer element and of the apoE receptor binding domain for other polymorphisms that could affect risk of AD. In particular, a C/G polymorphism at position +113 of the apoE mRNA in the apoE intron 1 enhancer element (IE1) has been recently identified. We found no other polymorphisms. We studied the relationship of the two alleles of the IE1 polymorphism with AD and found an apparent association between IE1 G and AD (n = 94; p = 0.0515). However, the IE1 G allele is also closely associated with apoE epsilon 4 (p < 0.0001). When the presence of apoE epsilon 4 is covaried, the association between the IE1 G allele and AD is no longer statistically significant (odds ratio = 1.29, 95% confidence interval: 0.44, 3.78). In contrast, epsilon 4 is still highly associated with AD when IE1 G is controlled for (odds ratio = 5.91, 95% confidence interval: 3.29, 10.63). Furthermore, there is no significant association between the age of onset of dementia and the inheritance of the G allele. We believe that the apparent association between IE1 G and AD is a consequence of the association between the epsilon 4 and IE1 G alleles. 相似文献
63.
Donald E. Sharp James Bailey Irving Hyman 《Journal of the American Ceramic Society》1931,14(11):820-826
An apparatus is described by means of which annealing data on glass may be rapidly and accurately obtained. Essentially, the apparatus consists of a mechanical means straining the glass, an optical means of measuring the stresses, and a means of heating the sample uniformly while making the measurement. The results are consistent and expressed in definite terms. The specimens for test may be quite small. The apparatus may be used for control purposes in place of measuring softening temperatures. 相似文献
64.
Psychology, education, and schooling: Social policy implications in the lives of children and youth. 总被引:1,自引:0,他引:1
Offers a broad perspective on the problems that face schools and related areas of interface between professional and academic psychology, educators, and the public. School psychology is discussed as a practice that has historically received too little attention. One result is the growth of problems affecting consumers and the psychology community. These are discussed in a broader perspective of the economy, social justice, the generation gap, and the growing trend of punitiveness toward children and youth. Suggestions for social policy planning are offered. (7 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
65.
Paul S. Chinowsky Hyman Brown Alberto Szajnman Allison Realph 《Canadian Metallurgical Quarterly》2006,132(2):118-124
The traditional civil engineering-based approach to construction engineering and management education focuses significant attention on core subjects such as scheduling, estimating, and contracts. This paper introduces an alternative approach to this education based on the concepts of project-based learning. Through the introduction of courses developed by the writers, the paper provides a foundation for changing current education approaches from a lecture-based format to a project-based format. In this format, students are challenged with open-ended problems requiring greater application of multiple engineering concepts as well as requiring interaction with outside experts from within the construction industry and related professions. An outline for a project-based learning course is presented with experiences and lessons learned from four implementations of the course. Student responses are presented to indicate the potential benefits of such an approach. This finding is further supported by the introduction of the Knowledge Landscape concept for construction education that emphasizes greater use of context, scope, and multiple intelligences in construction engineering education. 相似文献
66.
Insect pests and plant diseases reduce cassava yields substantially, posing a threat to food security throughout the developing
world. While agricultural scientists have recognized these threats, few assessments of the geographic distribution of cassava
pests and diseases have been made at the global scale. The goal of this study is to make such an evaluation for four key biotic
constraints to cassava production in developing countries: whiteflies, cassava green mites, cassava mosaic disease and cassava
brown streak disease. Occurrence records were obtained from laboratory and biodiversity databases and from the scientific
literature. These records were then used in ecological niche models to predict the potential distribution of cassava pests
and diseases. The distribution maps were cross validated by holding back 20% of the occurrence records. Potential distribution
maps were developed by combining the results of the best ecological niche models. Hotspots for potential cassava pest and
disease outbreaks include the Mato Grosso in Brazil, northern South America, the African rift valley, the southern tip of
India and much of Southeast Asia, where all four biotic constraints show high potential suitability. Our work highlights how
potential geographical shifts in infestation hotspots for several cassava biotic constraints will require intensified monitoring,
evaluation and research to prevent yield losses and ensure food security. 相似文献
67.
Rajkumar Kumarathasan Satya N. Chaudhuri Norman R. Hunter Hyman D. Gesser 《Journal of the American Oil Chemists' Society》1992,69(12):1260-1262
The effect of thioanisole and trimethylene sulfide on the autoxidation and yellowing of methyl linolenate has been investigated
by nuclear magnetic resonance (NMR) and ultraviolet visible spectroscopy, respectively. The progress of autoxidation was followed
by measuring the NMR integration of vinylic protons with respect to methoxy protons, which served as the internal standard,
as a function of time. The degree of yellowing was determined by measuring the difference in absorbance at 400 nm and 450
nm as a function of time. Both thioanisole and trimethylene sulfide enhanced the autoxidation of methyl linolenate. Inhibition
of yellowing was observed only with trimethylene sulfide. 相似文献
68.
Andrews Judy A.; Tildesley Elizabeth; Hops Hyman; Li Fuzhong 《Canadian Metallurgical Quarterly》2002,21(4):349
Data collected from 294 young adults, ages 19 to 25, and both a same- and an opposite-gender best friend or mate across 3 annual assessments were analyzed to examine the similarity to and influence of the peer on the young adult's substance use. The authors found similarity across time between both peers and the young adult in cigarette use, alcohol use, binge drinking, and, in most cases, marijuana use. In prospective analyses, peer use predicted young adult cigarette use, binge drinking, and problem use by the young adults. Results were generally consistent across gender and for both same- and opposite-gender peers. Findings emphasize peer influence contribution to young adult substance use and suggest the design of interventions that involve both young adults and their peers. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
69.
Ozechowski Timothy J.; Turner Charles W.; Hops Hyman 《Canadian Metallurgical Quarterly》2007,12(3):317
This article demonstrates the use of mixed-effects logistic regression (MLR) for conducting sequential analyses of binary observational data. MLR is a special case of the mixed-effects logit modeling framework, which may be applied to multicategorical observational data. The MLR approach is motivated in part by G. A. Dagne, G. W. Howe, C. H. Brown, & B. O. Muthén (2002) advances in general linear mixed models for sequential analyses of observational data in the form of contingency table frequency counts. The advantage of the MLR approach is that it circumvents obstacles in the estimation of random sampling error encountered using Dagne and colleagues' approach. This article demonstrates the MLR model in an analysis of observed sequences of communication in a sample of young adult same-sex peer dyads. The results obtained using MLR are compared with those of a parallel analysis using Dagne and colleagues' linear mixed model for binary observational data in the form of log odds ratios. Similarities and differences between the results of the 2 approaches are discussed. Implications for the use of linear mixed models versus mixed-effects logit models for sequential analyses are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
70.
RT Matthews MF Beal J Fallon K Fedorchak PL Huang MC Fishman BT Hyman 《Canadian Metallurgical Quarterly》1997,4(2):114-121
Differential scanning calorimetry was used to characterize thermal events associated with freezing and melting of suspensions and extracts of Panagrolaimus davidi, an Antarctic nematode which can survive intracellular freezing. Nematode suspensions produced a single freezing exotherm with a shoulder on the peak representing the freezing of the nematodes. A shoulder on the peak of melting endotherms indicates the melting of the nematodes and of the water surrounding them. Exotherms were also detected from individual nematodes mounted in liquid paraffin. The freezing of nematodes was very rapid and in marked contrast to that of freezing-tolerant insects and vertebrates, which take hours or days to freeze. Eighty-two percent of the nematodes' body water froze. High levels of survival were obtained in nematodes exposed to temperatures down to -40 degrees C. No additional thermal events were observed after the freezing event and before the melting of samples cooled to -40 degrees C, indicating no changes in the proportion of body water frozen. Ice nucleating activity is present in nematode suspensions but not in supernatants from nematode extracts. No thermal hysteresis activity was detected in nematode extracts. 相似文献